Comcast Corp. said Monday it will be streaming HBO and Cinemax shows, movies and other content online to 5,000 subscriber households in a national trial set to start in coming weeks. It is the first time the two premium movie channels will be offering their programs over the Internet to computers. Downloads to mobile devices may come in the future.

HBO and Cinemax will join TNT, TBS and Starz in Comcast’s online video trial. If the technical test is successful, Comcast will roll out access coast-to-coast to its subscribers at no additional cost.

The trial is part of a joint effort with Time Warner Inc. to offer cable programming on the Internet as viewership increasingly moves outside of the living room. But programmers and pay-TV operators will provide access only behind a walled garden of subscribers.

Unveiled last month, the venture dubbed “TV Everywhere” by Time Warner and “On Demand Online” by Comcast began with TNT and TBS.

Having been a step behind in the race to pipe entertainment from the Internet to television screens, struggling video rental-chain Blockbuster Inc. is counting on a new partnership with Samsung Electronics America Inc. to regain ground on rival Netflix Inc.

In an alliance announced Tuesday, Samsung’s next generation of high-definition TVs will include a built-in feature that will enable people to rent the latest DVD releases from Blockbuster with the press of a button on the remote control.

The Blockbuster rentals, expected to be priced from $1.99 to $3.99 apiece for 24-hour viewing opportunity, will be piped over high-speed Internet connections. Samsung’s HDTVs will begin offering Blockbuster’s on-demand service this fall.

The relationship is a coup for Dallas-based Blockbuster because Samsung is the world’s largest manufacturer of flat-screen TVs. Blockbuster’s on-demand rental service also will be accessible through software installed on Samsung’s Blu-ray DVD players and home theater systems - devices that already offer Netflix’s own Internet streaming service.

Twitter seems to be the hottest thing in tech recently — if you look at TechCrunch, it averages at least 3 posts a week about Twitter. But the bigger question is, who is really using Twitter? Many of you might think that, as with most of the latest gadgets and technologies, teenagers are using Twitter, but you’re wrong, and here’s why. Matthew Robson, a 15 year old intern, over at Morgan Stanley, wrote a report on how teenagers are consuming media, and why Twitter isn’t the hot topic in high school halls.

If you look at technologies trending with teens right now, it’s Apple devices (iPhone, iPod), smart phones (Blackberry, Palm), and then social networks (Facebook and MySpace). At least that’s what I see from hanging out with 1,500 other teenagers in high school every day (I am 16 years old). But why not Twitter? Well, because Twitter is a different type of social network than Facebook. Facebook is about connecting people, and sharing information with each other. The way my friends and I see it, Facebook is a closed network. It’s a network of people and friends that you trust to be connected to, and to share information like your email address, AIM screen name, and phone number. You know who’s getting your status messages, because you either approved or added each person to your network.

With Twitter, it’s the exact opposite. Anyone can follow your status updates. It’s a completely open network that makes teenagers feel “unsafe” about posting their content there, because who knows who will read it. Sure, you get emails notifying you when you have new followers, but that doesn’t compare to the level of detail you get when someone on Facebook adds you, and you get their information.

The service, which Microsoft aims to have ready by the end of July, will offer users the chance to stream music for free and also download to own.

Peter Bale, executive producer of MSN, Microsoft’s news and entertainment portal, told The Telegraph exclusively: “Music is an important area for Microsoft. We are looking at launching a music streaming service imminently.

It will be a similar principle to Spotify but we are still examining how the business model will work.”

Spotify users can stream music for free in exchange for listening to around a minute of advertising every half hour but for £9.99 a month, the ads will be turned off. It is thought Microsoft’s offering will be ad-supported too as well as having a paid-for premium service.